Ultracold atoms in a radiofrequency-dressed optical lattice

Nathan Lundblad, Patricia J. Lee, Ian B. Spielman, Benjamin L. Brown, John Obrecht, William D. Phillips, and Trey Porto

            We load ultracold atoms (obtained via Bose-Einstein condensation) into an optical lattice of dramatically nonstandard unit-cell shape, created by the radiofrequency (rf) dressing of a strongly spin-dependent bare lattice created by interfering laser beams. This rf coupling changes the unit cell of the lattice at a sub-(optical)-wavelength scale such that its curvature and topology departs strongly from that of a simple sinusoidal lattice, and in certain limits is ringlike. Such a lattice is generally interesting from a band-structure engineering perspective, and more specifically from a need for optical potentials that will realize increasingly complicated solid-state analogues. Radiofrequency dressing has previously been performed at length scales from millimeters to tens of microns, but not at the single-optical-wavelength scale. At this length scale significant coupling between adiabatic potentials leads to nonadiabatic transitions, a classic quantum-mechanical problem, which we characterize. We investigate the dressing itself via time-of-flight observation of the atomic momentum distributions.

Postdocs:      Nathan Lundblad, Patricia Lee, Ben Brown, John Obrecht

Submitter:     Nathan Lundblad

Mentor:         Trey Porto

Division:        Atomic Physics (842)

Laboratory:   Physics

Building:        216

Room:           B249

Mail Stop:     8424

Telephone:     301-975-5913

Fax:               301-975-8272

Email:            nathan.lundblad@nist.gov

Sigma Xi:       none are members

Category:      Physics